Furnace for roasting ores.



PATENTED AUG. 22,` 1905.

8 SHEETS--BREET 1.

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PATBNTBD AUG. 22, 1905.

W. TQRUSHTON.

FURNACE POR ROASTING DRES.

APPLICATION FILED DBG. 1B, 1903.

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W. T. RUSHTON. FURNAGE FOR R-OASTING GRES.

APPLICATION FILED DEG. 16, 1903.

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No.- 797,915. PATBNTED AUG. 22, 1905. w. T. RUsH'roN.

FURNACE FOR ROASTING GRES.'

APPLICATION FILED DEO.16, 1903.

8 SHEETS-SHEET 4.

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EURNAGE Fos ROASTmG DRES.

.APPLICATION FILED DBO, 16, ,1903.

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PATENTBD AUG. 22, 1905.

W. TfRUSHTON.

FURNAGE FOR ROASTING DRES.

APPLICATION FILED DEO. 16, 1903.

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10.797.915 I I PATENTBD AUG. 2z, 1905. w. T. RUsHToN.

PURNAGE PoR RoAsTING GRES.

APPLICATION FILED DEO.16, 1903.

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PATENTED AUG. 22, 1905.

W. T. RUSHTON. PURNACB FOR ROASTING GRES.

APPLIOATION FILED DBO. 16, 1903.

8 SHEETS-SHEET 8.

UNTTED STATES PATENT OFFICE.

FURNACE FOR ROASTING CRES.

Specification of Letters Patent.

Patented Aug. 22, 1905.

Application filed December 16, 1903. Serial No. 185,394.

To fl/ZZ whom, 1125 771,04/ concern:

Be it known that I, WILLIAM THOMAS RUSH- TON. a subject of the King of England, residing at London, England, have invented certain new and useful improvements in or Relating to Furnaces for the Roasting of Ores, of which the following is a specification.

This invention relates to furnaces for the roasting of ores, and has for its object to construct an apparatus which may be continuously in operation, an intermittent charging taking place at one point and a corresponding discharging being effected at another.

According' to this invention the furnace comprises one or more rotating cylindrical mufiies having internal spiral flanges whereby the material under treatment is conveyed from end to end of the cylinder as the latter rotates. Cross projections orinclined baffles are preferably arranged between adjacent iianges projecting laterally therefrom, so as to assist in moving the material. The cylinder is provided with fixed ends through which the material to be treated is conveyed in and out, lopenings being also provided for the admission of air and steam and for the exit of gases and vapors. Conveniently two such cylinders are disposed one above or near the other in such a way that the material after being fed into one end of one cylinder passes out at the other end, whence it is led into the second cylinder, from which it is ultimately conveyed away. The feeding into and from each cylinder is effected conveniently intermittently by means of suitable valves controlled by cams on the ends of the cylinder or otherwise, as found desirable. Preferably the initial feed takes place through an intermediate chamber or hopper. which serves as a trap and also as a means for measuring the quantity of material delivered, so that this may be effected at a uniform rate. The discharge from the first cylinder is preferably continuous, the material passinginto the hopper, the delivery from which is intermittently opened Ito allow the contents to enter the second cylinder., The discharge from the second cylinder takes place in a similar manner, the material being dumped in trucks or deposited in a eonveyer. or otherwise disposed of, as found desirable.

The cylinders may be constructed in various ways; but conveniently they are formed in sections supported on broad bearing-wheels .mounted on shafts disposed beneath the cyllannular toothed wheels mounted on the end of each cylinder. Each annular pinion is fianged inwardly and mounted on the end of the cylinder, so as to form an annular recess in which rests the periphery of the disk closing the end of the cylinder.

The disk is preferably formed of 4two metal plates secured together and inclosing a layer' of asbestos which projects around the periphery of the plate and forms a sufficiently tight joint. These end plates do not rotate, but are rigidly carried on bracket-arms or cross-pieces which are in turn mounted on the furnacewalls. Cams for operating the charging and discharging' hopper Valve are preferably mounted on the flanges of the annular pinions.

The heating apparatus below the rotating cylinder comprises burners of suitable type which are supplied with gas and air from convenient sources and are arranged immediately below the cylinders. Adjacent to these burners and in the burner-chamber are cylindrical or other compartments into which air is introduced for the purpose of being heated before it is conveyed to the interior of the cylinders. These air-heating chambers may be disposed close to the burners and preferably on either side thereof.

In the accompanying drawings, Figure l is a longitudinal central section, partly in elevation, of one form of furnace constructed in accordance with this invention. Fig. 2 is a horizontal section on the line 2 2 of Figs. 3 and 4. Fig. 3 is a front elevation of the furnace. Fig. 4 is a back elevation of the same. Fig. 5 is a longitudinal section of a modified form of furnace constructed in accordance with this invention, and Fig. 6 is a side elevation of a portion of the same.

Like letters indicate like parts throughout the drawings.

Referring to Figs. 1 to 4, on a base A rests the outside easing of the furnace comprisingv an arched fire-brick chamber A. The ends of this chamber are closed by cast-iron plates A2, which fit into grooves in the brickwork A. Supported in bearings in these ends A2 are two rotatable cylinders B and C, one above the other. Each cylinder is formed in sections, which are connected by faucet and spigot joints B and C. The cylinders B C consist of iron castings provided with internal projectingI spiral flanges B2 C2, whereby the material under treatment is conveyed from end to end of the cylinder as the latter rotates,

. these flanges preferably tapering and being of such a depth and so spaced apart as to enable the requisite amount of material to be coped with and moved at the desired rate. Cross projections or baffles B3 G3 are arranged between adjacent anges, projecting laterally therefrom and inclined downwardly on the upward-moving side of the cylinder. The object of these projections is to keep the ore constantly changing its position, and by inelining them as described the ore, which is carried some distance up the side of the cylinder during its rotation, rolls down in a constant stream and is turned over as it rolls.

Each section of the cylinder is separately sup-` ported on broad bearing-wheels l), mounted on a shaft D, disposed beneath'the cylinder and carried at its ends in bearings in the furnace-walls A2. The cylinders are rotated by a worm E and worm-wheel F through pinions G, engaging with annular toothed wheels H, mounted on the end' of each cylinder. These annular pinions H are provided with inwardly-projecting fianges H and mounted on the ends of the cylinders, so as to form at the end of each cylinder an annular recess in which rests the periphery of a fixed disk J, closing the end of the cylinder. The disk J is preferably formed of two metal plates secured together and inclosing a layer of' asbestos, which projects around the periphery of the disk and forms a sufficiently-tight joint. These end plates J do not rotate, but are rigidly carried on bracket-arms or cross-pieces K, mounted on the furnace-walls A2. In these end plates J are formed the necessary openings through which the material is fed into and delivered from the cylinders. The plate J at one end of the cylinder B is provided with an inlet J for air and a second inlet J2 for steam. The plate at the opposite end has an outlet J 3 for the gaseous products evolved by the process of roasting. The apparatus for feeding the material to be treated com-v one valve M at its inlet and a second valve M at its outlet which discharges into the cylinder B. Both valves are operated bya pivoted lever N, controlled by a spring N and actuated by a cam O on the rotating end of the cylinder. Normally the valve M is opened and the hopper M is filled; but when the cam yOcomes in contact with the valve-lever the valve M is closed, the valve Mfisopened, and.

the contents of the hopper M are discharged into the cylinder B. When the cam O leaves the valve-lever, the valve M2 is closed again and the valve M opened.

Referring to Fig. 4L, the discharge from the first cylinder B is preferably continuous, the material passing into the hopper M3, the discharge-valve M'L of which is intermittently opened by the action of the cam O on the lever N12, so as to allow the contents to enter the second cylinder. The discharge from the second cylinder C takes place in a similar manner, the material being dumped in trucks or deposited in a conveyer or otherwise disposed of, as found desirable. The heating apparatus below the rotating cylinders comprises burners P, which are supplied with gas through pipes Q from the gas-mains Q and with air through pipes R from air-mains R. Adjacent to these burners P and in the burnerchamber are cylindrical compartments S, into which air is introduced for the purpose of being heated before it is conveyed to the cyl-v inder air-inlets J. These air-heating chambers S are disposed close to the burners P and on either side thereof.

Referring to Figs. 5 and 6, which illustrate some modifications of the furnace constructions, the cylinder-sections may conveniently.

be connected by means of flanges T, secured together by bolts T. In order to allow of adjustment of the adjacent sections to insure exactA may discharge into a fixed bonnet U, arrangedv at the end of the cylinder and provided with an outlet-flue U. This bonnet is tapered at the bottom into a discharge-outlet U2, in which is suspended a flap-valve U3, which opens outward to allow of the discharge, but,

will not open inward to allow a back draft of air.

This invention has been describedfas applied to a furnace having two cylinders in series; but it is to be understood that it is` equally applicable to a furnace provided with aily number of cylinders in series or in para el.

The whole apparatus as above described enables the treatment of the materials to be carried out continuously, the feed and discharge being regulated in accordance with the requirements of the material under treatment. l discharging and yfor inlet and outlet of airA The feed and discharge are effected convenientl y by gravity, the arrangement being such as above described, so that the material can enter and leave the cylinders without cold air being allowed to have access to the interior, while the fumes therefrom are allowed to escape freely.

I/Vhat I claim as my invention, and desire to secure by Letters Patent, isi l. In a continuous roasting-furnace, the combination of a refractory furnace-chamber, a rotatable cylindrical munie mounted therein having an intern al spiral conveying-flange and bafiies projecting laterally from each side of the flange and inclined downwardly on the u pwardly-moving side.

2. In a continuous roastingfurnace, the combination of a refractory furnace-chamber, a rotatable cylindrical mufiie mounted therein having an internal spiral conVeying-fiange, inclined baffles projecting laterally therefrom, an inwardly-directed flange fixed on each end of the cylinder forming an annular recess, stationary disks closing the cylinder ends and resting in these annular recesses and means for rotating the cylinders.

3. In a continuous roasting-furnace, the combination of a refractory furnace-cham ber, a rotatable cylindrical muffle mounted therein having an internal spiral conveying-flange, inclined baffles projecting laterally therefrom, an inwardly-directed flange fixed on each end of the cylinder forming an annular recess, stationary disks closing the cylinder ends and resting in these annular recesses and comprising two metal plates secured together', a layer of asbestos inclosed between the plates, openings for charging and discharging and for inlet and outlet of air and other gases, bracketarms mounted on the furnace-chamber and fixed to the disks and means for rotating the cylinders.

4. In a continuous roastingfurnace, the combination of a refractory furnace-chamber, a rotatable cylindrical mufl'le mounted therein having an internal spiral conveying-flange, inclined baffles projecting laterally therefrom, an inwardly-directed flange fixed on each end of the cylinder forming an annular recess, stationary disks closing the cylinder ends and resting in these annular recesses, an annular toothed wheel on each fiange and means for rotating the wheels.

5. In a continuous roasting-furnace, the combination of a refractory fu rnace-chamber, two rotatable cylindrical muflies mounted therein in series one above the other and each having an internal spiral conveying-fiange throughout, inclined bafiies projecting laterally therefrom, means for rotating the cylinders, an inwardly-directed iiange fixed on each end of each cylinder forming an annular recess, stationary disks closing the cylinder ends having openings for charging and and other gases, bearing-shafts under the cylinders and a series of bearing-wheels on the shafts disposed beneath the cylinders.

6. In a continuous roasting-furnace, thel combination of a refractory furnace-chamber, two rotatable cylindrical muffles mounted therein in series one above the other, each having an internal spiral conveying-flange throughout, inclined baffles projecting laterally therefrom, means for rotating the cylin ders, an inwardly-directed fiange fixed on each end of each cylinder forming an annular recess, stationary disks closing the cylindervends and resting in these annular recesses, having vopenings for charging and discharging andfor inlet and outlet of air and other gases, an annular toothed wheel on each flange, means for rotating the toothed wheel, bearing-shafts under the cylindersA and a series of bearing-wheels on the shafts disposed beneath the cylinders.

7. In a continuousroasting-furnace, the combination of a refractory furnace-cham ber, two rotatable cylindrical muflies mounted therein in series one above the other, each having an internal spiral conveying-flange, stationary disks closing the ends of the cylinders and having openings for charging and discharging vand for inlet and outlet of airv and other gases, means for rotating the cylinders, a feed-hopper disposed near the inlet tothe upper cylinder, an intermediate chamber connected therewith and with the charging-V inlet, a first valve between the hopper and the chamber, a second valve between the chamber and the charging-inlet, and means for intermittently and simultaneously opening the second valve and closing the first valve.

8. In a continuous roasting -furnace, the combination of arefractory furnace-chamber,

two rotatable cylindrical mufiies mountedr therein in series one above theV other, each having an internal spiral conveying-flange, stationary disks closing the ends of the cylinders and having openings for charging and discharging and for inlet and outlet of air and other gases, means for rotating the cylinders, a feed-hopper disposed near the inlet to the upper cylinder, an intermediate chamber connected therewith and with the charginginlet, a first valve between the hopper and the chamber, a second valve between the chaml ber and the charging-inlet, a pivoted lever connected to the two valves, a cam on the inlet end of each cylinder arranged to operate the lever intermittently to open the second Valve and close the lirst.

9. In a continuous roasting-furnace, the combination of a refractory furnace-chamber,

two rotatable cylindrical mufiies mountedv therein in series one above the other, means for intermittently charging and discharging each cylinder, stationary disks closing the cylinder ends having openings for charging and to this specification 1n the presence of two subscribing Witnesses.

WILLIAM THOMAS RUSHTON.

Witnesses:

HARRY B. BRIDGES, CLAUDE S. R. MGKENZIE. 

